Acetylcholine is known as neurotransmitter playing an important role in cognition and mental functions in the central nervous system. Lowering of the cholin function is suggested to cause neurological and psychotic symptoms in Alzheimer's diseases, senile dementia of Alzheimer type, Huntington's chorea, Pick's diseases and senile dyskinesia. Particularly, intellectual deficits (concerning memory and cognition) are considered to result from lowered functions of acetylcholine-related central nervous system. An acetylcholinesterase inhibitor such as physostigmine, a precursor of acetylcholine such as choline and lecithin, or an acetylcholine receptor agonist such as arecoline have been used in clinical trials with these diseases [refer, for example, to S. Hirai; Clinical Neurology, 1, 200 (1983)]. However, these drugs have no therapeutical benefit, have severe side effects, and narrow range of the effective dose. Under the circumstances, there has been a demand for a new drug capable of selectively activating central cholinergic nervous system and effective for the treatment of above-mentioned diseases with little side effect.